Prosthetic limbs have seen many advancements allowing greater functionality. A prosthetic lower limb generally includes a prosthesis socket into which the amputated limb is placed. The fit and comfort of the prosthesis socket will in many instances determine the functionality level of the wearer. If the fit between the prosthesis socket and the limb is not adjusted properly, and is even painful, the prosthesis will see only minimal use. A problem that arises with properly fitting a rigid prosthesis socket to soft human tissue is the variance that occurs in the volume of the living tissue over the course of a day or over a period of days and even weeks. Diurnal, menstrual, and other fluctuations in body weight of the amputee can lead to changes in the volume of the amputated limb, which then affects the fit of the limb to the prosthesis socket. Accordingly, it has been a concern among professionals how to fit or interface living, variable soft tissue to a rigid prosthesis socket.
Prior art sockets are made with a fixed interior volume suited to match the limb volume of the intended wearer. Over time, the wearer may need to replace the socket with a newer socket with a greater or lesser volume. In the interim, the wearer usually makes do by, for example, stuffing the socket with socks, sponges, and the like.
In U.S. Patent Application Publication No. US 2009/0281637 A1, herein incorporated by reference in its entirety, the assignee of the present application sought to address this concern by providing a vacuum system in a prosthetic limb. This publication discloses the evacuation of air from spaces existing within the socket that results in a secure fit and improved suspension of the residual limb in the socket. Notwithstanding this improvement, there is a continuing need to improve the fit of a prosthesis socket and thereby, raise the functionality level of the wearer.